1. Field of Invention
The present invention relates to a method of manufacturing a press mold for mass-producing a hot stamping cold trim and a press mold for mass-producing a hot stamping cold trim manufactured using the same, and more particularly, to a method of manufacturing a press mold for mass-producing a hot stamping cold trim capable of significantly decreasing a cost required to develop a mold that may perform press-cutting on a 150 kg-level steel sheet and increasing a lifespan of the mold by improving strength of steel at a minimum cost through diffusion bonding, and a press mold for mass-producing a hot stamping cold trim manufactured using the same.
2. Description of Related Art
Currently, in accordance with a high oil price age in which an international oil price has continuously surged after 2002, an ultimate object capable of increasing competitiveness against other companies in a vehicle industry is to improve fuel efficiency of a vehicle. In order to improve the fuel efficiency, lightness of a vehicle body has been urgently demanded.
Therefore, carmakers of all the countries of the world as well as component producing companies supplying related components to these carmakers have developed a more excellent material and have produced vehicle body components using various materials having a higher toughness such as 490 MPa→4590 MPa→4980 MPa, in order to decrease a weight of a vehicle body component as light as possible and increase durability. However, as the material has gradually become tough as described above, a moldability problem that it is difficult to mold the material in a desired form has been generated. Therefore, various molding methods such as a hot stamping method, and the like, rather than a general press molding method have been introduced. The hot stamping scheme indicates a hot stamp scheme of increasing a tensile strength of the material to 150 kg by heating a temperature of the material to 600° C. to mold the material and then cooling the material.
FIGS. 1A and 1B are cross-sectional views showing states before and after an edge of a material is cut using a steel mold made of a general cold alloy tool steel (SKD-11) according to the prior art, respectively. As shown in FIGS. 1A and 1B, when an edge of a product 10 molded in a predetermined form is to be cut, in the case in which the product 10 is made of a 150 kg-level steel sheet, a steel rigidity problem that the product 10 molded in the predetermined form and made of the 150 kg-level steel sheet may not be trimmed using a steel mold 20 made of the cold alloy tool steel (SKD-11) is generated, such that a trimming work may not be continuously performed, which causes a decrease in a mass-production property.
In order to solve this problem, the entire steel mold 20 may be made of a superhard alloy such as a superhard steel or a powder high speed steel so that the product made of the 150 kg-level steel sheet may be easily trimmed. However, since the superhard alloy is very expensive, a press mold cost is significantly increased, which causes an excessive increase in a cost of a produced product and decrease competitiveness.
In consideration of these problems, some companies have produced a product in a scheme of laser-cutting an unnecessary edge portion of the product using a laser processing device as disclosed in Korean Utility Model Registration No. 0127057 (Korean Utility Model Laid-Open Publication No. 1996-004214) mentioned in the following Prior Art Document.
That is, as shown in FIG. 2, which is a view showing a state of cutting an edge of a product using a laser processing device according to the prior art, a product molded using a 150 kg-level steel sheet is laser-cut along a form of the product using the laser processing device 30 in a state in which it is disposed on a work jig 40. However, in this scheme, since the product is laser-cut along the edge of the form in the molded product, an excessive cutting time and an excessive cutting cost are required to complete one product, which causes an increase in a cost and significantly decrease price competitiveness.
The information disclosed in this Background section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.